Sulfur dioxide-induced exacerbation of airway inflammation via reactive oxygen species production and the toll-like receptor 4/nuclear factor-κB pathway in asthmatic mice.

Sulfur dioxide (SO2) is a common air pollutant that can exacerbate asthmatic airway inflammation. The mechanisms underlying these effects are not yet fully understood. In this study, we investigated the effects of SO2 exposure (10 mg/m3) on asthmatic airway inflammation in ovalbumin-induced asthmatic mice. Our results showed that SO2 exposure alone induced slight airway injury, decreased superoxide dismutase activity, and increased nuclear factor-κB (NF-κB) expression in the lungs of mice. Moreover, SO2 exposure in asthmatic mice induced marked pathological damage, significantly increased the counts of inflammatory cells (e.g., macrophages, lymphocytes, and eosinophils) in bronchoalveolar lavage fluid, and significantly enhanced malondialdehyde and glutathione levels in the lungs. Moreover, the expression of toll-like receptor 4 (TLR4), NF-κB, pro-inflammatory cytokines (e.g., tumor necrosis factor α and interleukin-6), and type II T-helper cell (Th2) cytokines was found to be elevated in the mice exposed to SO2 and ovalbumin compared to those exposed to ovalbumin alone. These results suggest that SO2 amplifies Th2-mediated inflammatory responses, which involve reactive oxygen species and TLR4/NF-κB pathway activation; these can further enhance Th2 cytokine expression and eosinophilic inflammation. Thus, our findings provide important evidence to understand a potential mechanism through which SO2 may exacerbate airway asthmatic inflammation.

Clinical and Biological Implications of Mutational Spectrum in Acute Myeloid Leukemia of FAB Subtypes M0 and M1.

BACKGROUND/AIMS: Acute myeloid leukemia (AML) of French-American-British (FAB) subtypes M0 and M1 are both poorly differentiated AML, but their mutational spectrum and molecular characteristics remain unknown. This study aimed to explore the mutational spectrum and prognostic factors of AML-M0 and M1. METHODS: Sixty-five AML patients derived from The Cancer Genome Atlas (TCGA) database were enrolled in this study. Whole-genome sequencing was performed to depict the mutational spectrum of each patient. Clinical characteristics at diagnosis, including peripheral blood (PB) white blood cell counts (WBC), blast percentages in PB and bone marrow (BM), FAB subtypes and the frequencies of known recurrent genetic mutations were described. Survival was estimated using the Kaplan-Meier methods and log-rank test. Univariate and multivariate Cox proportional hazard models were constructed for event-free survival (EFS) and overall survival (OS), using a limited backward elimination procedure. RESULTS: Forty-six patients had more than five recurrent genetic mutations. FLT3 had the highest mutation frequency (n=20, 31%), followed by NPM1 (n=18, 28%), DNMT3A (n=16, 25%), IDH1 (n=14, 22%), IDH2 (n=12, 18%), RUNX1 (n=11, 17%) and TET2 (n=7, 11%). Univariate analysis showed that age ≥60 years and TP53 mutations had adverse effect on EFS (P=0.015, P=0.036, respectively) and OS (P=0.003, P=0.004, respectively), WBC count ≥50×109/L and FLT3-ITD negatively affected EFS (P=0.003, P=0.034, respectively), whereas NPM1 mutations had favorable effect on OS (P=0.035) and allogeneic hematopoietic stem cell transplantation (allo-HSCT) on EFS and OS (all P< 0.001). Multivariate analysis suggested that allo-HSCT and NPM1 mutations were independent favorable prognostic factors for EFS and OS (all P< 0.05), WBC count ≥50×109/L was an independent risk factor for EFS (P=0.002) and TP53 mutations for OS (P=0.043). CONCLUSIONS: Our study provided new insights into the mutational spectrum and molecular signatures of AML-M0 and M1. We proposed that FLT3-ITD, NPM1 and TP53 be identified as markers for risk stratification of AML-M0 and M1. Patients with AML-M0 and M1 would likely benefit from allo-HSCT.

Higher EZH2 expression is associated with extramedullary infiltration in acute myeloid leukemia.

Accumulating evidence indicates that enhancer of zeste homolog 2 (EZH2) promotes the metastatic ability of solid tumors, but the role of EZH2 in extramedullary infiltration (EMI) in acute myeloid leukemia (AML) has not been thoroughly explored. In the present study, we investigated the possible association between EZH2 and EMI. We found that the messenger RNA (mRNA) and protein expression levels of EZH2 in AML patients were both significantly higher than in idiopathic thrombocytopenic purpura (ITP) patients. Furthermore, a positive correlation between EZH2 mRNA expression and percentage of peripheral blood blasts wa s found in AML patients (r = 0.404, p = 0.009). The migratory capacities of Kasumi-1 and HL-60, which both show a high level of EZH2 expression, were markedly higher than those of U937 and KG-1α. In contrast, silencing of EZH2 resulted in reduction in proliferation and migration ability and an increase in apoptosis. The latter observation was accompanied by reduced expression of associated proteins p-ERK, p-cmyc, and matrix metalloproteinase 2 (MMP-2) and an increase in epithelial cadherin (E-cadherin). These data suggest that higher expression of EZH2 may be associated with extramedullary infiltration in acute myeloid leukemia and affect pathogenesis via activation of the p-ERK/p-cmyc/MMP-2 and E-cadherin signaling pathways.

[Ceramide participates in cell programmed death induced by Type II anti-CD20 mAb].

OBJECTIVE: To explore the exact mechanisms of programmed cell death (PCD) induced by Type II anti-CD20 mAb in CD20+ non-Hodgkin lymphoma (NHL) cells, and to provide theoretical basis for anti-tumor ability of new CD20 mAb.
 METHODS: After incubation with Rituximab (a Type I anti-CD20 mAb) and Tositumomab (a Type II anti-CD20 mAb), Raji cells were stained by annexin V & propidium iodide (PI). The ratio of programmed death cells were measured by two channel flow cytometry (FCM). Before the treatment of anti-CD20 mAbs, Raji cells was incubated with a caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]- fluoromethylketone (Z-VAD-FMK) and a dihydroceramide synthase inhibitor fumonisin B1 (FB1) for 30 minutes to assess their inhibitory effect on PCD. High performance liquid chromatography (HPLC) was utilized to compare the ratio of programmed death cells between the pretreatment group (treated by Rituximab and Tositumomab) and the non-pretreatment group. The anti-CD20 mAbs-treated Raji cells were collected, and the ceramide levels in the Raji cells in the different pretreatment groups were also examined by HPLC, and the inhibitory effect of FB1 on the changes of ceramide levels in the Raji cells was measured. The Raji cells were incubated with different concentration C2-ceramide, C2-Ceramide-induced PCD was also evaluated by annexin V & PI staining after 16 hours. 
 RESULTS: Tositumomab (10 µg/mL) but not Rituximab (10 µg/mL) can induce significant PCD (28.6±4.2)% in Raji cells, with significant difference (t=26.48, P<0.01), which cannot be blocked by Z-VAD-FMK with a concentration range from 10 to 30 µmol/L (F=3.01, P>0.05). The cellular ceramide levels in Raji cells were significantly elevated after the treatment of Tositumomab (t=28.48, P<0.01). C2-ceramide can significantly induce PCD in Raji cells in a dose-dependent manner with a concentration range from 5 to 40 µmol/L (F=2.71, P>0.05). The dihydroceramide synthase inhibitor FB1 can significantly inhibit the elevated cellular ceramide levels (F=20.18, P<0.01) and cell programmed death induced by Tositumomab (F=17.02, P<0.01).
 CONCLUSION: Type II but not Type I anti-CD20 mAbs can induce caspase independent PCD in CD20+ NHL cells through the elevation of cellular ceramide levels. The PCD is not associated with classic caspase pathway.

An exopolysaccharide from Bacillus subtilis alleviates airway inflammatory responses via the NF-κB and STAT6 pathways in asthmatic mice.

Bacillus subtilis is an intestinal probiotic for immune homeostasis and its exopolysaccharide (EPS) is known to possess anti-inflammatory and antioxidant properties. The underlying mechanisms are not yet fully understood. In the present study, we investigated the effects of the EPS (50, 100, 200 mg/kg) on airway inflammation in asthmatic mice. Our results showed that EPS treatment of asthmatic mice significantly alleviated pathological damage in the lungs, remarkably decreased the counts of total inflammatory cells including lymphocytes, and eosinophils in the bronchoalveolar lavage fluid (BALF) and reduced indexes of oxidative damage. Moreover, the expression of type II T-helper cell (Th2) cytokines (interleukin- (IL)4 and -5) subsequent to EPS treatment was found to be dramatically down-regulated in a concentration-dependent manner. Additionally, the EPS treatment reduced JAK1, STAT6 and nuclear factor-κB (NF-κB) expression in the lungs of asthmatic mice. Taken together, these results suggest that the EPS from B. subtilis alleviates asthmatic airway inflammation, which involves the reduction in reactive oxygen species (ROS) and the down-regulation of the STAT6 and NF-κB inflammatory pathways, which can further reduce Th2 cytokine expression and eosinophilic inflammation. Thus, our findings provide a potential mechanism through which the EPS mitigates asthma, suggesting that the EPS could be a potential source of an anti-asthmatic drug.

Potential antitumor and anti-inflammatory activities of an extracellular polymeric substance (EPS) from Bacillus subtilis isolated from a housefly.

Bacillus subtilis, a probiotic, has been applied in the medical, food, and feed industries among others. However, the mechanisms of its benefits to hosts are not yet fully understood. Here the characterization and bioactivities of an extracellular polymeric substance (EPS) from Bacillus subtilis were investigated to reveal its partial mechanisms and provide the theoretical basics for further development and utilization of Bacillus subtilis. In this study, the novel strain Bacillus subtilis xztubd1 (GenBank: MG458322.1) was isolated from a housefly's body, identified according to phenotypical and genotypical analyses, and found to produce large amounts of an EPS. Through ultraviolet spectroscopy and Fourier transform infrared spectroscopy (FTIR spectroscopy), the EPS was found to contain a variety of chemical functional groups, such as O-H groups, C=C, C=O, CH3, C-O-H and C-O-C bonds, and alpha-type pyranose. Furthermore, the in vitro antioxidant activity of the EPS on DPPH radicals at a concentration of 90 µg/ml was 62%; on the superoxide radical at a concentration of 90 µg/ml, this value was 75%; and on hydroxyl radicals at a concentration of 90 µg/ml, the activity was 54%. EPS also enhanced significantly phagocytosis, lysozyme activity in macrophages, IL-2 content in mice and inhibited dramatically the growth of HeLa cells. These results showed that the EPS with reductive groups have the strong capacity to scavenge reactive oxygen species (ROS), reinforce the immune system and inhibit the growth of cancer cell, which helps theirs hosts defence against many diseases, including inflammation and cancer. The EPS from Bacillus subtilis has the potential to be an anticancer and anti-inflammatory drug candidate in the pharmaceutical industries, which provide scientific evidence for the development and utilization of probiotic-derived medicines.

High expression levels of SMAD3 and SMAD7 at diagnosis predict poor prognosis in acute myeloid leukemia patients undergoing chemotherapy.

The SMAD family (SMAD1-9) was critically important for regulating cellular process through transforming growth factor-ß signaling pathway, and contributed to carcinogenesis; however, their prognostic roles in acute myeloid leukemia (AML) remained unclear. This study collected 84 de novo AML patients treated with chemotherapy and 71 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Kaplan-Meier survival estimate indicated that among SMAD1-9, high SMAD3 and SMAD7 expression were both associated with poor event-free survival (EFS) and overall survival (OS; all P < 0.05) in AML patients undergoing chemotherapy; and high SMAD6 expression was associated with shorter EFS and OS (all P < 0.01) in patients underwent allo-HSCT. Multivariate analysis showed that only high SMAD7 expression had adverse effect on EFS and OS (P = 0.021, 0.026) independently. Furthermore, High SMAD3 and SMAD7 expressers had significantly shorter EFS and OS than low expressers (P = 0.006, 0.001). In AML patients who went through allo-HSCT, there were no significant differences for EFS and OS between patients with high and low-expression SMAD3 or SMAD7. Our study suggested that high expression of SMAD3 and SMAD7 predicted adverse prognosis in AML patients undergoing chemotherapy and SMAD7 was a better prognostic marker than SMAD3. Their prognosis impact may be overcome by allo-HSCT.

High expression of microRNA-500 is associated with poor prognosis in patients with acute myeloid leukemia receiving allogeneic hematopoietic stem cell transplantation.

MicroRNA-500 (miR-500) is a potential prognostic biomarker in a number of different types of cancer, such as prostate cancer and hepatocellular carcinoma. This study aimed to explore the clinical implications of miR-500 expression status in patients with acute myeloid leukemia (AML) that had received allogeneic hematopoietic stem cell transplantation (allo-HSCT). miR-500 expression status and clinical data were obtained from 74 patients with AML in the The Cancer Genome Atlas database receiving allo-HSCT. Patients with low expression level of miR-500 (miR-500low) were significantly more likely to present with a French-American-British classification M2 subtype (P=0.003), and less likely to have the M5 subtype (P=0.040) compared with patients with high expression levels (miR-500high). miR-500low patients were associated with low-risk AML (P=0.003) and core-binding factor subunit b-myosin heavy chain 11 translocation mutation (P=0.021). There was a significant difference in nucleophosmin 1 (P=0.009), NRAS proto-oncogene GTPase/KRAS proto-oncogene GTPase (P=0.047) and PHD finger protein 6 (P=0.040) expression levels between the two groups. miR-500high patients had a decreased overall survival (OS) time compared with the low expression group (P=0.035). Multivariate analysis revealed that miR-500 expression significantly affected OS time independent of other classical prognostic factors, such as age and common mutations. The analysis of survival curves further substantiated this result. The results obtained in the current study suggested that miR-500 may be a suitable prognostic marker for patients with AML receiving allo-HSCT.

Down-regulation of miR-203a by lncRNA PVT1 in multiple myeloma promotes cell proliferation.

INTRODUCTION: Emerging evidence has indicated that long non-coding RNAs (lncRNAs) play vital roles in multiple myeloma (MM) development and progression. However, the underlying mechanism of PVT1 in MM remains unclear. MATERIAL AND METHODS: QRT-PCR was used to detect the expression of PVT1 and miR-203a in MM samples and cell lines. The effects of PVT1 on MM cell proliferation and apoptosis were determined by CCK8 assay and flow cytometer assay, respectively. Bioinformatics methods were used to identify the downstream target miRNAs of PVT1. RESULTS: We found that the expression of PVT1 was upregulated in MM samples and cell lines (p < 0.05), while the expression of miR-203a was downregulated in MM samples and cell lines (p < 0.05). There was a negative correlation between PVT1 expression and miR-203a expression in MM samples (p < 0.05). In in vitro function assays, we found that PVT1 inhibition suppressed MM cell proliferation and induced MM cell apoptosis (p < 0.05). The bioinformatics approach predicted that PVT1 sponge miR-203a would modulate MM cells. Rescue experiments confirmed the recovering roles of miR-203a for PVT1 on MM progression. CONCLUSIONS: In the present study, we found that lncRNA PVT1 could promote MM cell proliferation and induce cell apoptosis by inhibiting miR-203a expression. Therefore, PVT1 may represent a potential therapeutic target for the treatment of MM patients.

Mutational spectrum and prognostic stratification of intermediate-risk acute myeloid leukemia.

The mutational spectrum and prognostic stratification of intermediate-risk acute myeloid leukemia (IR-AML), which accounts for a substantial number of AML, are unclear. In order to explore the prognostic significance of the mutational spectrum in IR-AML, 106 IR-AML patients were collected from The Cancer Genome Atlas database. Sixty-two patients underwent chemotherapy-only, forty-four proceeded to allogeneic hematopoietic stem cell transplantation (allo-HSCT). Fifty-five patients had more than five recurrent genetic mutations. NPM1 had the highest mutation frequency, followed by DNMT3A, FLT3, RUNX1, IDH2, IDH1, and TET2. In all patients, allo-HSCT was an independent favorable factor for EFS and OS (P = 0.036, P = 0.001, respectively); age ≥60 years, FLT3-ITD and mutations in DNMT3A and RUNX1 were independent risk factors for survival (all P < 0.05). In the chemotherapy-only group, multivariate analysis showed that age ≥60 years was an independent risk factor for EFS and OS (P = 0.008, P = 0.017, respectively). In the allo-HSCT group, multivariate analysis indicated that MLL-PTD was an independent risk fact for EFS (P = 0.037), FLT3-ITD and RUNX1 mutations independently contributed to poor OS (P = 0.035, P = 0.014, respectively). In conclusion, older age was an important risk factor for IR-AML patients undergoing chemotherapy-only; FLT3-ITD, MLL-PTD and RUNX1 mutations were significant risk factors for IR-AML patients who received allo-HSCT.

Oridonin effectively reverses the drug resistance of cisplatin involving induction of cell apoptosis and inhibition of MMP expression in human acute myeloid leukemia cells.

Cisplatin is the first generation platinum-based chemotherapy agent. However, the extensive application of cisplatin inevitably causes drug resistance, which is a major obstacle to cancer chemotherapy. Oridonin is a diterpenoid isolated from Rabdosia rubescens with potent anticancer activity. The aim of our study is to investigate the role of oridonin to reverse the cisplatin-resistance in human acute myeloid leukemia (AML) cells. The effect of oridonin on human AML cell proliferation was evaluated by MTT assay, cell migration and invasion were evaluated by transwell migration and invasion assays in cisplatin-resistant human AML cells. Furthermore, cell apoptosis was examined by flow cytometry. The inhibitive effect of oridonin in vivo was determined using xenografted nude mice. In addition, the expressions of MMP2 and MMP9 were detected by Western blot. There was a synergistic antitumor effect between cisplatin and oridonin on cisplatin-resistant human AML cells in vitro and in vivo. In addition, the combination of cisplatin and oridonin synergistically induced cell apoptosis. Furthermore, the combination treatment not only inhibited AML cell migration and invasion, but more significantly, decreased the expressions of MMP2 and MMP9 proteins. Our results suggest that the synergistic effect between both agents is likely to be driven by the inhibition of MMP expression and the resulting increased apoptosis.

Identification of novel molecular markers for prognosis estimation of acute myeloid leukemia: over-expression of PDCD7, FIS1 and Ang2 may indicate poor prognosis in pretreatment patients with acute myeloid leukemia.

Numerous factors impact on the prognosis of acute myeloid leukemia (AML), among which molecular genetic abnormalities are developed increasingly, however, accurate prediction for newly diagnosed AML patients remains unsatisfied. For further improving the prognosis evaluation system, we investigated the transcripts levels of PDCD7, FIS1, FAM3A, CA6, APP, KLRF1, ATCAY, GGT5 and Ang2 in 97 AML patients and 30 non-malignant controls, and validated using the published microarray data from 225 cytogenetically normal AML (CN-AML) patients treated according to the German AMLCG-1999 protocol. Real-time quantitative polymerase chain reaction and western blot were carried out, and clinical data were collected and analyzed. High Ang2 and FIS1 expression discriminated the CR rate of AML patients (62.5% versus 82.9% for Ang2, P = 0.011; 61.4% versus 82.2% for FIS1, P = 0.029). In CN-AML, patients with high FIS1 expression were more likely to be resistant to two courses of induction (P = 0.035). Overall survival (OS) and relapse-free survival (RFS) were shorter in CN-AML patients with high PDCD7 expression (P<0.001; P = 0.006), and PDCD7 was revealed to be an independent risk factor for OS in CN-AML (P = 0.004). In the analysis of published data from 225 CN-AML patients, PDCD7 remained independently predicting OS in CN-AML (P = 0.039). As a conclusion, Ang2 and FIS1 seem related to decreased CR rate of AML patients, and PDCD7 is associated with shorter OS and RFS in CN-AML. Hence, PDCD7, Ang2 and FIS1 may indicate a more aggressive form and poor prognosis of AML.